A known structure of a composite solar battery, includes a dye-sensitized solar cell arranged on a light-incident surface side, and a crystalline silicon solar cell arranged on the side opposite to the light-incident surface of the dye-sensitized solar cell (i.e., on a rear side). According to this structure, the dye-sensitized solar cell can make use of short wavelengths of sunlight and the crystalline silicon solar cell can make use of longer wavelengths of the sunlight.
However, this composite solar battery has a structure wherein the two independent solar cells are combined one on top of the other; therefore, wiring is required to connect the individual solar cells to each other. As a result, the battery production process may be complex, and the photoelectric conversion efficiency low.
Furthermore, for thin-film photoelectric conversion devices small holes may develop in the surface caused by manufacturing defects. These small holes are often referred to as “pinholes” or “pinhole defects”. These pinholes may cause leakage currents that decrease the efficiency and output of thin-film photoelectric conversion devices.
Therefore, there is a need for combined photoelectric conversion devices with high photoelectric conversion efficiency, which may be produced easily and minimizes defects from pinhole defects.